#include "../../apue.h"
#include <netdb.h>
#include <errno.h>
#include <syslog.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/wait.h>

#define QLEN 10

#ifndef HOST_NAME_MAX
#define HOST_NAME_MAX 256
#endif

extern int initserver(int, struct sockaddr*, socklen_t, int);

void serve(int sockfd)
{
    int clfd, status;
    pid_t pid;

    for ( ; ; )
    {
        clfd = accept(sockfd, NULL, NULL);
        if (clfd < 0)
        {
            syslog(LOG_ERR, "ruptimed2: accept error: %s", strerror(errno));
            exit(1);
        }

        if ((pid = fork()) < 0)
        {
            syslog(LOG_ERR, "ruptimed2: fork error: %s", strerror(errno));
            exit(1);
        }
        else if (pid == 0)
        {
            /*
             * The parent called daemonize (Figure 13.1), so
             * STDIN_FILENO, STDOUT_FILENO, and STDERR_FILENO
             * are already open to /dev/null. Thus, the call to
             * close doesn't need to be protected by checks that
             * clfd isn't already equal to one of these values.
             */
            if (dup2(clfd, STDOUT_FILENO) != STDOUT_FILENO ||
                dup2(clfd, STDERR_FILENO) != STDERR_FILENO)
            {
                syslog(LOG_ERR, "ruptimed2: unexpected error");
                exit(1);
            }
            close(clfd);
            execl("/usr/bin/uptime", "uptime", (char*) 0);
            syslog(LOG_ERR, "ruptimed2: unexpected return from exec: %s",
                   strerror(errno));
        }
        else
        {
            close(clfd);
            waitpid(pid, &status, 0);
        }
    }
}

int main(int argc, char* argv[])
{
    struct addrinfo* ailist;
    struct addrinfo* aip;
    struct addrinfo hint;
    int sockfd, err, n;
    char* host;

    if (argc != 1)
        err_quit("usage: ruptimed2");
#ifdef _SC_HOST_NAME_MAX
    n = sysconf(_SC_HOST_NAME_MAX);
    if (n < 0)
#endif        
        n = HOST_NAME_MAX;
    host = malloc(n);
    if (host == NULL)
        err_sys("malloc error");
    if (gethostname(host, n) < 0)
        err_sys("gethostname error");
    daemonize("ruptimed2");
    hint.ai_flags = AI_CANONNAME;
    hint.ai_family = 0;
    hint.ai_socktype = SOCK_STREAM;
    hint.ai_protocol = 0;
    hint.ai_addrlen = 0;
    hint.ai_canonname = NULL;
    hint.ai_addr = NULL;
    hint.ai_next = NULL;
    if ((err = getaddrinfo(host, "ruptime", &hint, &ailist)) != 0)
    {
        syslog(LOG_ERR, "ruptimed2: getaddrinfo error: %s", gai_strerror(err));
        exit(1);
    }
    for (aip = ailist; aip != NULL; aip = aip->ai_next)
    {
        if ((sockfd = initserver(SOCK_STREAM, aip->ai_addr,
                                 aip->ai_addrlen, QLEN)) >= 0)
        {
            serve(sockfd);
            exit(0);
        }
    }
    exit(1);
}
